This app was mentioned in 3 comments, with an average of 1.33 upvotes
none actually you cannot use two or more inputs I mean the buttons on most of those apps and the lag defeats the purpose of trying to use it for any emulation type stuff . I am just ponying up for a controller and dongle for pc.
for phones these are alot of Chinese made usb type c compatible ones you can try .
this app worked for me for a while now but the lag just makes it worst for trying to do stuff in windows in general.
https://play.google.com/store/apps/details?id=com.mmh.mobilegamepad